The 100-million-year-old fossils had originally been discovered in 1971 in Canada's Northwest Territories, but the bones lay untouched and unexamined for 25 years (see Canada map).

"I did my undergraduate work here [at Alberta]," said Michael Caldwell, the co-author of the new find, "and I was studying specimens right on top of this table [as an undergrad]."

Caldwell graduated in 1986 and came back to the university as an assistant professor in 2000. Shortly after his arrival, he got some money to renovate the lab.

"We decided it was time for the Ping-Pong table to go," he said. "We lifted it up, and found all this marine reptile material underneath. We knew the boxes were there, but we didn't know what was in them."

The bones belong to two juvenile ichthyosaurs, one slightly larger than the other, and two adults, one of which has two embryos preserved near its vertebrae.

"It's important stuff," Caldwell said. "This is right at the end of the evolutionary history of the ichthyosaurs. They go extinct right after this."

Caldwell's team published their findings in the September issue of the journal Palaeontology.

Newest Known Embryos

The embryos found with the specimens are by far the newest known80 million years more recent than the oldest previously known ichthyosaur embryos.